Microchaete sp. B

Mcgregor, Glenn B., 2018, Freshwater Cyanobacteria of North-Eastern Australia: 3. Nostocales, Phytotaxa 359 (1), pp. 448-450 : 448-450

Microchaete sp. B . Fig. 64 A–F.

Filaments solitary, or more commonly clustered into small groups, flexuous, 4.2–5.3 μm wide, attached to the substratum along the basal region. Sheath fine, colourless, not lamellated, sometimes absent. Trichomes cylindrical along the entire length, not or slightly constricted at the cross walls. Vegetative cells isodiametric up to 1.6 × longer than broad, 3.1–7.2 μm long × 3.8–5.6 μm wide; apical cells conically-rounded. Heterocytes basal and intercalary, basal heterocytes spherical to slightly conical, 4.3–9.1 μm long × 4.3–5.3 μm wide, intercalary heterocytes cylindrical. Akinetes not observed.

Specimens observed:—Booloumba Ck at camping area #1.

Observations:—Growing amongst colonies of Nostoc in the littoral zone of shallow streams, on rocky substrate. The slightly conical shape of the terminal heterocytes is distinctive, and unlike other known Microchaete species.